Assighstqs to herbert s



H. K. SANDELL.

EHONOGRAPH STOP.

APPUCAHON FILED JULY 5, ISIS Patented July 1, 1919.

5 SHEETS--SHEET 1.

A Q W %%x H.-K. SANDELL.

PHONOGRAPH STOP.

APPLICATION FLED JULY 19x6.

Patentcd J nly I, 1919. 5 SHEETS-SHEE1 2 H. K. SANDELL. PHONOGRAPH STUF.

. APPLICATION FILED JULY 5.1916.

Patented July 1, 1919.

SHEET 4.

5 suns-- H. K. SANDELL.

PHONOBRAPHSTGP.

MPLICATION mas JULY 5, i915.

1 308,447. Patented July 1, 1919.

5 SHEETSSHEET 5.

UNITED STATES PATENT OFFICE.

HENRY K. SANDELL, OF CHICAGO, ILLINOIS, ASBIGNOR TO HERBERT S. MILLS, OI CHICAGO, ILLINOIG.

PHONOGRAPH-STOP.

Specification of Letters Patent.

Patented July 1, 1919.

Application filed July 5. 1918. Serial No. 107.581.

To all whom it may concern:

Be it known that I, HENRY K. SANDELL, a citizen of the United States, residin at Chicago. in the county of (ook and t tate of Illinois. have invented a new and useful lhonograpli-Stop, of which the following is a specification.

My invention relates to improvements in phonographs and more particularly to the control nu-chanism of phonographs the rec ord tables of which are electrically driven. The specific object of the invention is to provide improved control devices for efiecting the starting and stopping of the'electric motor by which the record table is driven. The invention will be fully understood from the following specification taken in connection with the accompanying drawings in which Figure 1 is a top plan view of a phonograph embodying my invention; Fig. 2 is 'a transverse section through the case of the machine, taken on the line 2 of Fig. 1; Fig. 3 is a similar section taken on the line 3 of Fig. 1, parts of the mechanism being shown in elevation; Fig. 4 is a sectional view taken transversely of the table-shaft and showing the construction of the current-interrupting device mounted thereon; Fig. 5 is an enlarged detailed section through one of the brushes of the current-interrupting device shown in Fig. 4; Fig. 6 is a section on the line 6 of Fig. 2, the casing being removed; Figs. 7 and 8 are enlarged plan views showing two positions of the combined switch and brake mechanism; Fig. 9 is a section on the line 9 of Fig. 8; Fig. 10 is a section on the line 10 of Fig. 1; and Fig. 11 is a diagrammatic view showing the electric connections of the motor.

Referring more particularly to the drawing, the numeral '12 designates a generally rectangular box-like casing which houses the working parts of the machine. Upon the bottom of this casing there is mounted a frame casting 13, which provides bearings for the vertical table-shaft 14, the latter being held in its assembled position with refercnce to the frame by a collar 15 secured tln-reon by a set-screw, as shown in Fig. 3. The table-shaft is shouldered adjacent its upper end, which projects outwardly through the top of the casing, the shoulder serving to support the table 16, which is of the usual disk form as to its upper surface,

and adapted to support upon its felt facing 17 a record-disk 18, which is centered and held in position by the projecting end of the table-shaft, as in ordinary phonograph constructions.

The table 16 is preferably formed of castiron and carries integral depending lugs 19 suitably spaced apart and extending downwardly through the aperture in the casing cover. The lugs 19 constitute armature poles of the driving motor of the machine,

eing arranged in a circle to succcssivel pass in front of the pole-pieces 20 of a shaped electromagnct, the legs of which are wound with coils 21. 22, the magnet being supported horizontally in the plane of the lugs 19 by the frame casting 13, as is shown in Figs. 3 and 6.

Between the collar 15 and the lower stephearing the table-shaft 14 carries a currentinterrupting device. such device being in the form of a metallic drum 23, insulated from the table-shaft by a bushing 24 and having inset in its cylindrical surface a row of insulating plugs 25, equal in number to the lugs 19. For cooperating with the drum 23 there are provided brushes 26, 27, vertically disposed, one above the other, and supported in the insulating block 28 carried by the frame 13. From Fig. 5 it will be seen that each of the brushes 26. 27 is provided with a bore 29 in the end adjacent the drum, which bore, receives the spring-held contact 30 of the brush. The brush 26 contacts with the drum 23 in the plane of the insulating plugs 25, while the brush 27 bears upon the lower uninterrupted surfaceof the drum to constantly make contact therewith.

Bolted to a suitable boss on the frame 13 and arranged horizontally in the plane of the table-lugs 19 is a horse-shoe magnet 31 (Fig.6) the poles of which are. spaced apart a distance equal to the space between adacent lugs 19. so that the attraction exerted by the magnet will cause the table to come to rest at the position shown in Fig. 6. with a lug opposite each of the legs of the 1nagnet 31. electro-magnet poles 20 as to cause the lugs 10 nearest adjacent the electro-magnet poles to occupy the position shown in Fig. 6.

The combined switch andlhrake, mochanism of my phonograph is shown in detail in Figs. 7, 8 and 9. This mechanism comprises a stud 32 mounted in a plate 33 fas- This magnet is so related to the tened t0 the upper face of the casing and carrying on such upper face a thuml'i-wheel ill hymeans of which the stud may he manuall v operated. Beneath the plate tlil the stud has pinned thereto an arm 115 which has pivotally mounted on its outer end a bent le ver 36. one. end of which projeet's upwardly through a slot 37 (Fig. 1) in the plate 32} and earri s a friction block 38 adapted to contact with the periphery of the table 1 h heing normally held in engagement with the tahle lrv a small tension spring 39 having one end engaged with a pin on the lever 36 and the other end with a. pin on the arm :33. as is shown in Figs. '7 and 8. The end of the levdr fill opposite that whit-h engages the tahle is wedgoshapeel and ls provided with a mach lt) whit-h i adapte to engage a iin'll projecting through an insulating dot-k l2 mounted heneath the plate 33. The arm 3.3 i normally held in the position shown in Fig. 7 hr a small mil-spring 43 extending hetveen a pin on the arm and a pin ll tl igi ll, seuul'ed in the plate 33. will he clear from an inspection of Figs. 7 and H rotation of the stud 232 in a countereloekwise direction will eause the wedgeshaped extremity of the lever 36 to Slide over the pin ll until the nott'h 'ltl engages the pin. in which position the parts will hecome automatically ltlt'lit'll. A small electromagurt 4:) is supported with its poles adjacent the wedge-slzapedextremity of the lever It? in this loelted position of the latter. and the lever is constructed of magnetie metal or has secured thereto a magnetic metal armature which. upon the energizing l' the magnet l5 wil he a tracted toward the latter against the force of the spring PM to disengage the noteh ill from the pin 41 and remit the spring lfl to draw the parts hat-k to the position in which they are shown in Fig. 7.

The speed-regulating means fol my motor t'ompriseS an eleetrrrmagnet 50 '(Fig. 2). suitahly supported by the casting 13 and having a s 'iring-leaf 5| supported at one end and overlying the pole of the magnet, the lea l' prei'erahlv having secured thereto a 'oagnetie metal armature 52 which lies di reeliy above hut out of rontaet with the pole of the magnet 50. The effective length of the spring 51 may he altered hy adjustment ot a sliding ahntment 53, which travels heneat'h the leaf adjacent the fixed end thereof, the ahutment being arranged for adjustment along the length of the leaf as he the screw 54 the outer end of whi h projects through the casing 12 and is provided with a knurled "wheel 55 for convenient manual operation. A pair of insulating hloelts all. mounted aliove the fixed end of the spring 51. have Sttl'ltlWlCllCtl between them a eontaet-plate 57. which extends outwardly parallel to the spring, and the, up-

per of the two hint-ks 56 is preferahlv extended forwardly to provide a. journal in whieh is mounteda tonnterweightet eontart-lever F18. The lever 59 carries a verticall disposed carhon hrush 59 in its outer end, the hrush heing designed to normally Lear with a slight pre:-sure on the upper face ot' the plate 5? Fol a tuation of the lever 58 from spring 51, the form r carries a dowut'u rned toe-pieee t'itl the end of which clears the face of the spring 51 in the posi tion which the latter ort'lipies when at rest,

'lhe automatic stop mechanism for my phonograph is hest shown in Figs. 1 and 10. from which it. will be seen that the pivoted tone-arm (it. whit-h is adapted to swing a ross the lure of the record in the well understood manner. carries a pin 32. to the outer end of which is eeeured an insulated sleeve (33. A small ta e-plate (it is mounted in the are of movement of the contact meniher (if) and earries a stat ionar emit-art: in the torn: (i an ec entric (35 mounted upon a thnmh nlu ei shaft till. A spring interposed lietween the plate it and the nut on the end ot the thumlrwheel shaft exerts a suflieient longitudinal pressure upon the shaft to cause it to remain in any angular position in whit-h it may he set by manual operation of the thumb-wheel.

The eleetrical conne tions of the phonograph are illustrated h the diagram (Fig. 11 from which it will he seen that the pow r lines. designated 70. 71 and energized 'lroin an suit'ahle source of current supplv. are. in general, connected in series through the s'vitrln stieed-regulator. motor and eur rent'intcrrupting device. lhe automatic stop devire IL (in is connected in shunt with.

the parts mentioned and in series with the release magnets 45 of the switch. Both of the coils EL 22 oi the motor eleetrtrnmgnet are in series with the current-interrupting devil-e 23 but the coil 22 is shunted around the speed regulaton only the coil 21 being in series therewith. A condenser 75 is shunted around the speed regulator to minimize sparking at the ron aet points thereof.

The operation of the meehanism described is as follows: Assuming that the phonograph is at rest. and that it is desired to operate he same. the tlnur -wheel 34 of the startingswitch will he rotated in a counter rloeltwise dirertion. as viewed in Figs. 7 and 8. lly sueh rotation of the thuinhwheel 34 the tahle It? will he started in a t-loclnvise direction. h) reason of the movement of the friction surt'aee 38 in the springhehl lever Elli, the Friction snrt'aee serving as a driving memher. As the thumb-wheel approaches the limit of its eonnter-el oeltwise movement. the wedge shaped extremitv of the lever So will engage the insulated pin 11., and since the faceplate 33 which earries the thumb-wheel shaft and its connected parts is in circnit with the elcctromnuniets 2i. and the insulated pin 41 is connected with the lin wire 70. as illustrated by the. diagram. the circuit will be established through the operatin; parts of the niccle auism. At its iiniit of movement the wedgeshaped extremity of the tower Sit; is locked to the pin it hy the notch 40. as shown in Fig. H. so that the switch remains closeddhe circuit being completed therethrough.

As indicated by the diagrann the coil ot' the electro-inagnet is now in circuit with the energiied lines 7t). 71 through the interrupter iii, and the latter so arranged that with the parts ih the position shown in Fig. ti. the brush 26 bears upon the surface of the drum between two of the insulating plugs 35. The lugs 19 nearest the poles 20 of the rice? iii-magnet are therefore attracted to the said poles, causing the table to be operated in a clockwise direction. as shown in Fig. it. As the lugs reach a position opposite the polcs' 20. an insulating: plug: 25 rides under the brush it: to interrupt the circuit. and by th momentum of the. table the lattei' continues to revolve until the next adjacent lug has come into position to be acted upon by the magnetism of the poles it). at which time the insulating plug 25 will have traveled past. the hrush it; to permit the latter to once more complete the circuit and energize the magnet. The clectroanagnet coiipcrati ngr with the depending lugs or poles 19 of the table. and controlled by the commutator therefore constitutes a simple type of electric motor for continuously driving the table lit in a cloek ise direction. The, parts are so designed that the strength of the electt|)llt:l; flltt under the energizing current of the coil 22 is just suttieient to rotate the table at the lowest speed required of the latter under operating conditions.

'hiie the magnetron is energized im mcdiatcly upon the closing of the starting switch. the maguetcoil 21 is likewise so onergized. this circuit being completed by the carbon brush 59 of the contact lever 58 and by the contact plate 57. as illustrated in Fig. ll. Since the coil 50 of the speed regulator is likewise in series with the interrupter 23. the current through the coil will be constantly made and broken at a Speed depending! upon the speed of rotation of the tabie. Sui-h intermittent energizing and deenergizing of the coil 50 will cause the latter to intermittentlv attract and release the spring armature 5! supported above the same. It is well known that oscillatory or vibratory devices of the character of the armature 51 have. by virtue of their proportions. mass,

and elasticity. a certain natural periodic time of vibration or oscillation. If intermittent impulses of a frequency differing suhstanrially from the natural frequency of the vibrating element be impressed thereon,

very nllgllt motion of the vibratory element will take place. but as the impressed impulses approach the natural period of the vibratory element. the amplitude. of motion of the latter will become greatly inrrcaseil. it is upon these well known principlis that my speed-regulating device operates. As the frequency of the electrical impulses impressed upon the coil 50 by the commutator 23 increases. and approaches the natural frequency of the spring armature. 51. the latter will begin to vibrate. and the amplitude of its vibrations will increase. until at each vibration it is contacting with the toe 60 of the contact lever '58, ra ising the latter and breaking the circuit between the brush 5% and contact plate :37. At this critical speed, therefore. the circuit of the magnet coil '31 is interrupted during a portion of the cychof movement of the vibratory leaf 51. and the mean otter-tire value of the current in the coil 2! is thereby d creased. The amount. of this decrease will be dependent upon the amplitude of oscillation of the ribratory armature 51. for the reason that in general the periodic time of the oscillating contact lever 58 will considerably exceed that of the spring 51. and the hrush 59 will therefore remain out of contact with the plate iii not only during the time required for the spring 51 to complete that portion of its movement which lies in range of movement of the toe (it). but also during ;the greater time required for the lever to return to its normal position after it has been lifted 100 by the spring. in practice. therefore, I am able to effect complete control of the current in the coil :21 by meansof the vibrating armature 51. it being quite possible for the armature to vibrate with such amplitude 105 to keep the brush 59 entirely out of contact with the cohtact-plate 57. It will be quite clear from the foregoing that the power of the magnet. poles 20. and CODSPQHOHH) the speed of the table 17. is a factor of the 10 periodic time of the spring armature 51. To adjust the speed of the table t i therefore sufiicient to vary the periodic time of the vibratory armature. which may be conveniently effected from the exterior of the 115 phonograph through the knurled wheel 55, by means of which the sliding abutment; 53 may be advanced or retracted to change the effective length of the spring. The control thus provided is exceedingly delicate.

As the tone'arm 16 is fed across the face of the record by the sound-reproducing grooves therein, the contact member (33 will approach the eccentric 65. and if the latter has been properly adjusted the parts will on 125 gage when the end of the record is reached. Such engagement will close the shunt circuit through the release magnets 45. as is indicated in Fig. 11. and by the energizing of these magnets the lever 36 will be un- 0 latrhetl from the rontaet pin 41. whereupon the spring 4d will exert, its force o draw the arm 3? hack into the position in which it is shown in Fig. 7. By this automatic release of the starting switch the motor will he fit!" energized and simnltainaiusly the friction surface 39 will act as a brake upon the table to bring the latter quickly to a stop. It may here he. noted that the permanent magnet 31 will reuse the tahle. in general, to come to a rest in the position most advantageous for again starting the same. The, stationary magnetfis, he'iwever, merely SUPPlCJH-PHUKF Y to the starting switch. the pre erretl coin strurtion of the latter by which the tahle is. manually rotated simultaneously with the closing of the circuit being; in itself suttirient provision for the starting of the machine. Hint-e the friction surface 38 is subjert to Wear. however, and may therefore be uncertain in action, after long service. I prefer to provide the eleetro-magnet 31 as, an additional measure of precaution. By the use of this magnet, which prevents the motor from coming to rest; on a dead point, the more art of (losing the cireuit would at all times be sufficient to start the motor.

It may he noted as (-liaraet'eristie of my marhine that the partieular form of electrie motor whieh I have shown and tie sc ibed is of peruliar advantage in phonm graph eonstmetions, hy reason of the l'aet. that the table is inherently of great; weight, and theref re. serves its own lly-wheel. pre enting or minimizing those speeil varia- 'tions vihirh are pernliarly fatai in phono graphs herause of their etfert upon the piteh ol' the somnl whirh is reproduced.

\Vhile I have shown ainl tleserihetl in runsitlerahle detail one speritie emhotliment of my invention, it is to he unllrrstoorl that snrh showing and (leseription is illustrative only and for the purpose ol nothing rlear the nature and ohjeets of the invention. and that 1 (lo not regard the invention ill-7 limited to this partieular ronslruetion nor to any feature thereof exeepti in so far as i have ineiinleil sin-h limitations within the terms of the following elaims. m whieh ii i any intention to rlaim ail norelt. inherent. in my invention a ln'oadly as is permissible in view of the prior art.

What l I-laim as new ainl desire to seeure Irv Letters latrnl is:

1. in a phonograph. the romhinntion with a. I'tltil'tl tahle ainl a tone-arm :nlaptml to swim; in an are thereahore. oi a hrahe nn-rhanism monntecl ailjarent the edge of sahl tahle. :Hlll having a lerer p orilletl with an arm having a t'rirtion surface adapted to engage the bilge ol saitl tahle, a spring eon nertwl with saiil lever for normally maintaining su -h ngagement. means for holllinn saiil t'ri 'lion surface in inoperative po-i tion while a ltWllll is living pla 'etl. an elm-- li'olnagjnet mailing with saicl means. means for manually rel asing said trirtion .snrl'are aml simnltam-onsl imparting: a starting im pulse to said tallle. a plate pl'flVltltil with a ranrslot for 'uhlim; saitl arm to ranstthe frirtion sol-tare to impart snrh start m; nn polaainl then more out. of ronlin-t with said tahle, aml a rontart merlnlnisin artnilllll h .saiil ltllllfwll'lfl and ehgetrirallr rolr nertml with saill elertromagnet to release Silltl l'rietion surt'at-e holding means aml per mit tluapplic-ation of Hflltl ln'ake when the pla \in; ot' a rworil has iieen rompleiwl.

:2. in a phonograpln the ((Jllll)ill:ltlllll ill: a I'tllil'tl talile antl a tone-aim :ulaptetl lo swing in an are therraliove. of a lll'tllfl Illllllani m mounlial :nljaeent the e-clge ol' saiil tahle anal having :1 lever Pl'fH'ltltil with :in arm having: a friction nnrl'aee adapted to engage the i-ilgje of saiil lahh'. a sprin; eonlllltt l with aill lever For normally mainiainiin, surh engagement at lateh wanting with sa nl lever for holding saiil l'rirtion snrlac-e in inoperative position while :1 rev- UWl is living played. an elertrtunagm-t voarling nith saill lat-"h,- means For manually releasing saiil lrn'tion snrl'are ainl simultaneously imparting a starting impulse to saiil talile, a plate p oriiletl with :1 mm slot for ,Iltillllltf sahl arm to rause the l'rirtion snr t'awto impart llt'll startling impulse alnl then mo'e out of t'olilnrt with l 2\l\l lalilr. and a wontael nn-rhanism lt'lllill('(l lo sa'nl lone arm anil (-ha'trienlly ronneeti-tl wilh sanl elre-troniagnel to r lease saiil latch aml permit the appliration ol' sahl ln'alw when the pla).in; iii a reroril has la'rn roniplelei'l.

ll IINRY K. HANUELL 

